Nuclear energy has been used for several decades in the production of electricity. Many countries are adopting this method of power production for industrial and domestic applications owing to the numerous advantages it has over other methods of electricity production. Nuclear energy is produced in a process known as nuclear fusion. This process results in the production of high quantities of energy in form of heat and also in the production of electromagnetic waves called nuclear radiations. When released into the atmosphere, radiations cause adverse health effects that last for a long duration of time. It has been suggested that the effects of radiation at any given time surpass any poison in the world. This paper will discuss the process, production of radiation from nuclear power, the effects such radiations have on the health of workers, and preventive measures.
Nuclear fusion and electricity production
Radiations are invisible emissions that travel through matter including physical objects owing to their short wavelengths. Nuclear energy forms part of the sources of production of electricity in the world. Nuclear energy contribution to the production of electricity may be advantageous in the sense that it is economical, environmentally friendly, and safe if appropriate safety measures are applied.
To produce electricity using nuclear energy, a nuclear reactor is used. Nuclear reactors are designed to heat water using heat energy developed in the process of nuclear fusion to emit steam that rotates turbines in the process of electricity generation. The heat from the reactor comes through the process of nuclear fusion. The best element to use in this process is Uranium- 235. The nucleus of a Uranium atom contains positively charged protons and electrically neutral neutrons. For nuclear energy to be produced by nuclear fusion, the nucleus of the uranium atom must be split in a process that is aided by bombarding the atom with positively charged neutrons (Nuclear energy, 2009).
Uranium is introduced into the reactor with aid of small ceramic pellets. In an introduction into the reactor, Uranium is bombarded with neutrons causing it to break down. In this process, the neutrons of Uranium split into two nuclides in a process called binary fusion. This prompts a chain reaction when the slip neutrons collide with other atoms to cause more splitting of neutrons. The splitting of neutrons is accompanied by the emission of large quantities of heat that is used to heat water for steam production (Nuclear energy, 2009).
The temperatures in the reactor chamber are effectively controlled by the regulation of the number of pellets introduced in the reactor at a given time. The steam produced when water is heated is used to rotate turbines for electric power production. The total energy released in a single fusion in one atom is equal to 200Me V. It is estimated that the heat produced when one pellet the size of the end of a finger is equivalent to the heat produced by 149 gallons of oil, 157 gallons of gasoline, 1,780 lbs of coal and 19,200 cubic feet of natural gas. Therefore, the production of electricity using nuclear fusion has economic benefits far beyond any other energy production method for electricity production. One nuclear reactor can contain up to 18 million pellets. (Nuclear energy, 2009)
It is estimated that about 17% of the total electricity generated in the whole world is produced through the use of nuclear energy. Also, 20% of the total electricity produced in the United States of America is from nuclear energy (Nuclear energy, 2009).
Radiations as a by-product of the nuclear fusion process
As mentioned earlier, the process of nuclear fusion involves the splitting of Uranium atoms which result in the production of high quantities of energy in form of heat. In this process, radiations are given out as a by-product. Radiations are forms of energy in the form of electromagnetic waves. During the nuclear fusion process, electrons chaotically move in all directions causing a collision with other electrons. It is worth noting that radiations are produced as a result of the collision between electrons and not the other particles contained in the atoms. The collisions lead to loss of speed by electrons resulting in loss of energy. The lost energy is dissipated in form of photons. The collection of all the photons produced is usually referred to as radiations. The process of production of electromagnetic radiations by the method of collision of electrons is called bremsstrahlung which basically means “braking radiations” due to the deceleration of electrons. It has been shown that the rate of loss of energy through the production of radiations is higher at lower temperatures than the rate of heat production in the process of nuclear fusion. Also, as the temperature of the fusion process is increased, energy production and radiation losses increase. Ignition temperature is described as the temperature at which the rate of heat energy production is higher than the rate of loss of energy through radiations in any nuclear fusion process (Eliezer S and Eliezer Y, 2001: p 118)
When uranium undergoes a nuclear fusion process, the radiations produced include gamma rays, x-rays, and beta particles. These radiations have posed a major environmental and health hazard due to the adverse effects of the radiations whenever they leak into the atmosphere. In addition, the fusion process leaves a residue called fusion waste that is environmentally harmful.
Despite the enormous advantages of nuclear energy in the production of electricity, its use poses great health and environmental risk if the proper procedures are not adhered to in ensuring the safety of such plants, especially with regard to accidents prevention. Several countries have witnessed detrimental consequences as a result of accidents in nuclear plants. The effects of nuclear radiation from power plants are not different from the effects of nuclear weapons. Although nuclear energy is proposed as one of the safe methods of electricity production, its safety depends on the strict adherence to regulations in the operation of the reactor to prevent any accidental leakage of radiations. A typical example of the occurrence of accidental leakages in power plants is the case of Chernobyl in Ukraine in 1986 where it has been reported that it caused the death of approximately one hundred and fifty thousand people immediately. It is reported that its effects have been felt for a long time since the occurrence of the accident and are usually expressed in health problems like thyroid cancer and radiation contamination in soils, water, and food. The explosion caused contamination of soils miles away from the point of an explosion which left the soils unstable for agricultural use for many years. (Vesley, 1999: p 70)
The use of nuclear energy for the production of electricity has generated heated debate in the world due to the global danger posed if the safety of the plants is not guaranteed. Only a few developed countries have been able to successfully use invest in nuclear energy plants.
Shielding of the reactor
As a safety measure, the nuclear reactor is properly shielded to prevent leakage of radiation. Some safety devices are incorporated during the construction of the reactor to help in monitoring as well as preventing leakage of radiations. In absence of a proper mechanism to prevent leakage in a reactor, radiation can be released into the atmosphere and this can cause adverse effects not only to humans but also to the environment as a whole. Leakage is prevented through the use of radiations shields. The shield is put in place to enable radiations absorption within the reactor. Concrete and steel have been found to be excellent absorbers of radiations therefore the nuclear reactor is constructed with a heavy layer of the two components to act as the shielding material. It is reported that a typical reactor requires steel of a thickness of the order of half a meter to give sufficient shielding. In addition, still is reinforced by the addition of a few meters of concrete on top (Ricky, 2008).
For the workers in nuclear reactor plants, the effective radiation dose should not exceed 20millisieverts (mSv) per year considered in a period of five years and should not exceed 50 mSv. The standards for protective measures state that the annual equivalent dose of the eye should not be more than 150 mSv while that of any point of hand or skin should not exceed 500 mSv. In addition, a lot more regulations have been formulated in order to keep the radiation doses to health workers as low as possible (Stuklex, 2002).
Although it is reported that people living near power plants receive only a small amount of radiation doses, the health risk exposure to them cannot be overlooked. The closer the person is to the plant location the higher is the risk to exposure not only to the low radiation doses but also to more serious risks if accidents leading to radiation leakage occur in the plants.
The most commonly used units of measurement of radiation are rem and soviet. One sievert is equivalent to approximately 100 rems. Data shows that in the USA radiation dose absorbed by a person is approximately 360millirem annually and that twenty percent of radiation comes from manmade sources of radiations (Meshkati, 1999).
Workers in nuclear power plants use special gear to protect themselves from radiation and radioactive isotopes. During work, the amount of radiation at any instant is monitored to ensure that it is within the permissible level. The amount of radiation is detected using a Geiger counter which monitors the number of particles in the air as a result of radioactivity. The Geiger counter operation is triggered by the ionizing effect of the radiation particles. Geiger counters are available in various forms that enable the detection of different kinds of particles of radioactivity. Other old methods of detection of radiations involve the use of gold leaf electroscope in detecting radiations. However recently computerized radiation detection equipment has been produced. Motes are small electrical equipment that incorporates several sensors and a radio transmitter. The motes are capable of forming ad-hoc networks and transmitting data using radio links from one sensor to another. Motes are available in fixed and movable versions. The advantage of using motes over other radiation measurement equipment is that there is no need for a person to work in the areas where radiations are to be detected (Mani, 2008).
Health effects of nuclear radiation.
Radioactive contamination is described as the uncontrolled distribution of radioactive isotopes in a given environment (Poschl and Nollet, 2007: p 19). The contamination can be caused by wastes in nuclear energy plants that are not properly disposed of.
The debate on the environmental and health effects of radiation has developed discussions and arguments in relation to the use of nuclear energy in the production of electricity and the potential environmental and health effects such use pose not only to the immediate neighboring environment but also to the world as a whole. It has been found out that the short-term health effects due to exposure to radiation are skin burns. Radiation dangers have shown terrible effects and are more detrimental than any other poisons known to mankind, many forms of cancer including blood cancer (leukemia) and skin cancers have been found to be caused by exposure to nuclear radiation. The dangers posed by nuclear radiation in nuclear energy plants are no different from those caused by nuclear weapons. The extent of damage that can be caused by the deadly radiations can be experienced many miles from the location of the plant.
A major characteristic of radiations is that they cause ionization of the matter through which they penetrate. Also due to the short wavelengths of the electromagnetic waves, they are capable of penetrating through matter. The extent to which electromagnetic waves penetrate matter depends on the wavelength of the wave, the density of the matter, and its thickness. In regard to the health effects of radiations, the damage caused when the radiations interact with living cells is due to ionization and excitation. The excitation is results when atoms in the cell absorb energy from the radiation while in ionization, the radiation energy causes knocking off of some electrons from the atoms in the cell through which they move.
When cells are ionized and exited, they are damaged since many cells and molecules are held together by electrons. As radiations pass through cells, they pass their energies to electrons of chemicals in the cells to cause some electrons to be knocked away from the cells or molecules they are attached to. Agarwal (2003: p 162) gives an analogy of the damage caused to atoms and molecules in body cells by radiations through ionization and excitation to the situation where a powerful atomic explosion is capable of driving out the earth from its orbit. It is projected that when radiations pass through cells they may cause the cells to die or to be damaged either temporally or permanently.
One health effect of radiation is the ability to cause loss of cells or genetic mutation. When germ cells are exposed to radiations in the sperms or ovum it may lead to children with defects ranging from physical, mental, and genetic defects. It is reported that prolonged exposure to radiation causes a reduction in infertility. Radiations can also lead to mild mutations that are expressed in form of allergies like asthma, juvenile diabetes, hypertension, and physical and genetic malformation. The most common health effect of radiation is the development of cancer. Other than being caused by exposure to radiation in nuclear power plants, cancer problems can also emanate from exposure to radioactive elements used in nuclear fusion in these plants.
Environmental effects of radiation
The effect of radiations on the environment depends on the length of time the radiations stay in the atmosphere before they get depleted. This also depends on son the type of radioactive element emitting radiation. It is estimated that the effects of uranium-238 will be felt for 700 million years while those of Strontium- 90 will last for only 53 days. Several incidences of nuclear radiation to the environment have been witnessed where the growth and development of plants are significantly affected adversely. In extreme cases, radiations have caused plant damage affecting their productivity, germination of seeds, and even genetic mutation in growing plants which can potentially affect their ability to survive. The environmental effects of radiation can be learned from the Chernobyl nuclear reactor meltdown in 1986. It is reported that a large part of the ecosystem surrounding the nuclear plant several miles away was adversely affected. Although the response of different plant species to radiations is different, a large part of the ecosystem had been affected in the first year after the incidence. (Meshkati 1999).
The agricultural productivity in several countries neighboring Ukraine lowered due to radiation contamination following the disaster. Although much of the effects of radiation in Chernobyl were felt immediately, the effect t the environment was being felt several years after the disaster. Ten years after the disaster a report by international scientists in Vienna indicated that there were considerable contaminations in soils by radioactive elements contained in the reactor that exploded. The presence of these elements was not only detected in water but also in food chains. The effects of radiation were felt in an area of 125,000 km2 across Belarus, Ukraine, and Russia where forests were completely wiped out, water bodies and soils got contaminated by radioactive elements and a lot of animals were killed (Meshkati 1999).
It is evident that the environmental consequences of radiation are long-lasting. Although the effects of radiation fade with time, the need for the protection of incidences of radiations fallout cannot be overemphasized. In reality, every part of the environment is adversely affected when large amounts of radiation are released into the atmosphere.
Control strategies to limit exposure to radiation.
As mentioned earlier, the threat posed by the radiations from nuclear power plants can be felt immediately at the location of the plants as well as many miles away from the plant. In addition, the effects of radiation are long-lasting and can be felt for many years. Therefore, it is the responsibility of the relevant authorities to ensure that such power plants adhere to the already established regulations that are aimed at preventing the occurrence of any kind of radiation leakage from the nuclear reactors.
In nuclear power plants, workers are required to wear radiation measuring gadgets that can monitor the radiation doses so that they are protected from receiving radiation doses more than the are the legal limit. This includes teaching the workers at the stations on various aspects of radiation protection for them to be aware of the radiation hazards and the safety precautions in their work. Such protective measures involve zoning of the plants such that some areas with a higher risk of exposure to radiation are completely prohibited for access by workers. Radiations and radioactive elements enter the body by being absorbed through the skin, orally, or through inhalation. Workers are thus supposed to be well protected by wearing protective gear that reduces the chances of direct contact with the radioactive isotopes and the skin. The protective gear includes helmets, aprons, and shoes that prevent any exposure t radiation.
The most exposed persons to radiation are those in the immediate vicinity of the nuclear power plant. This mainly involves the workers. It is suggested that other people in a radius of 80 miles from the plants are also highly exposed to nuclear radiation. In 1979 Environmental Protection Agency (EPA) issued regulation standards that were aimed at protecting the general public from radiation from nuclear energy. These regulations incorporated the permissible levels of radiation doses that a person is expected to receive annually. The regulations demand that all nuclear power plants must have emergency plans for protecting the general public against exposure to radiation from radioactive materials used in power generation.
It is no doubt that nuclear energy will offer the solution to future electricity generation. Owing to the economic advantage and efficiency in using nuclear energy in relation to other methods of energy production, many countries will be forced to initiate nuclear plants for electricity production. Nuclear energy is not only being exploited in the production of electricity but also in many other applications. Still, more applications of nuclear energy can be projected especially with the concerns being raised regarding the environmental effects of fossil fuels not to mention the danger of their depletion.
The disadvantages of using nuclear energy cannot be overlooked. Several incidences have occurred where the real danger posed by the new technology to the environment and the human race in particular. The Chernobyl nuclear plant meltdown should serve as an indicator of the magnitude of danger in using nuclear energy. It can be concluded that the adverse effects of nuclear energy touch on every aspect of human life ranging from health, economic, political as well as social wellbeing. In addition, the environment, in general, is not spared. Although the most serious damage in case of accidents is seen immediately, long-term effects can be felt many years after the disasters happen.
The world organizations involved in monitoring and licensing of such plants should strengthen their policies to make sure that all nuclear plants meet the relevant safety requirement before they start operating. In addition, more advanced methods of detection of radiations should be put in place to enable detection of any abnormal levels of radiations ether from manmade sources or from natural causes.
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